[ 39 « ] 
ver leparated at all ; though I worked the machine 
for a longer time ; but on replacing the water, in 
a few feconds the balls diverged, as at firft. Thefe 
experiments I repeated feveral times, and always 
with the fame fuccefs. The fmoak, therefore, in 
the firft experiment; and the vapour of the hot 
water, in this laft ; was certainly the medium , 
which conveyed the electricity, from the prime- 
conduCtor, to the balls : and I think I may now 
very fafely pronounce, that smoak, and the vapour 
of hot water, are abfolutely conduB or s of eleblricity \ 
though fmoak is a far better one than the vapour 
of hot water, and both of them are exceedingly 
bad ones. 
Upon the queftion, whether vapour be a con- 
ductor of electricity ; I would obferve, that Dr. 
franklin’s curious experiment, of making a vi- 
able atmofphere, round an infulated, electrified 
body ; cannot be made, but in an exceedingly dry 
ftate of the air. The reafon is obvious ; but in a 
very dry day, I have often fiicceeded in the experi- 
ment ; and have ftsewed it to feveral of my friends, 
particularly Mr. marsham, and Mr. nairne. 
My method of doing it, is as follows: I place 
the brafs cafe of a fteel-yard weight- (about two and 
an half inches diameter,) upon a clean, dry, ftand 
of fealing wax: then having in readinefs, a green 
wax taper, with a longfmtjf, I give the infulated 
body, a fpark, from the knob of a pofitively 
charged bottle ; or take one from it, by the knob of 
a negatively charged one (the appearance is the 
fame in both cafes); then bringing the taper, juft 
blown out, very gently towards the infulated body. 
